中文摘要：

通过对沥青混合料AC-13C进行5种不同程度老化,然后再进行-5℃条件下的应力松弛试验,研究老化对其应力松弛性能的影响并建立耦合老化程度因子的松弛模量模型.对比不同老化程度沥青混合料的松弛模量曲线,发现老化程度与松弛时间之间存在一定的等效性;基于材料黏度的自由体积理论,通过假设沥青混合料的自由体积分数与老化程度间呈线性关系,研究并建立了沥青混合料的老化程度-松弛时间等效移位因子;对松弛模量主曲线分别采用Burgers模型和不同单元数目的广义Maxwell模型进行非线性拟合,表明广义Maxwell模型在表征松弛模量变化时优于Burgers模型,且单元数越多,拟合精度越高,考虑到拟合精度和参数数目,推荐采用六单元广义Maxwell模型,并建立耦合老化程度因子的松弛模量模型.

英文摘要：

By aging of asphalt mixture AC - 13C for 5 degrees and then conducting stress relaxation test on the aged samples at -5℃, the effect of aging on the stress relaxation of the asphalt mixtures is researched and the relaxation modulus model of asphalt mixtures coupled with aging factor is established. The comparison of relaxation modulus curvers of asphalt mixtures with different aging degrees shows that there exists the equivalence between aging degree and relaxation time. The equivalent shift factor between aging degree and relaxation time of asphalt mixture is founded based on the free volume theory of material viscosity through hypothesizing that there exists a linear relationship between fractional free volume and aging degree. Non- linear fitting on the obtained relaxation modulus master curve is conducted using Burgers model and the general Maxwell model with different elements respectively, which shows that the general Maxwell model is superor to the Burgers model in expressing the change of relaxation modulus, and the fitting precision increases with the increase of number of the elements. According to the fitting precision and the number of elements, the 6-element general Maxwell model is recommended, then the relaxation modulus model of asphalt mixture coupled with aging factor is established.